Over the last 50 years, the number of pathogenic and commensal bacterial strains resistant to antibiotics, and the number of antibiotics to which they are resistant have increased dramatically. As a result, infections that once were readily treatable by antibiotics may no longer be responsive to such treatments. Bacteria that develop resistance to antimicrobial treatments, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistan Enterococcus (VRE), is a well-recognized medical problem world-wide and has become one of the most important threats to modem health care.
For decades, vancomycin has outpaced the multidrug resistance of MRSA. It is now facing increased resistance by emerging vancomycin-intermediate S. aureus (VISA) and vancomycin-resistan Enterococcus. New antimicrobial agents and improved methods are thus needed for the treatment and prevention of infections caused by such pathogens.